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When to Plant Comfrey in Clark County, WI

Comfrey is a vigorous perennial herb valued as a dynamic accumulator of nutrients. Its leaves make excellent mulch, compost activator, and liquid fertilizer.

Clark County, Wisconsin is in USDA Zone 4b. The average last spring frost is May 13 and the first fall frost is September 30, giving you a growing season of approximately 140 days.

At an elevation of 850 feet, Clark County receives approximately 39.8 inches of rainfall annually with predominantly silt loam soil. Summer highs average 82°F, so choose short-season varieties of Comfrey to ensure they mature before fall.

Clark County, WI (Zone 4b) Short season
140 days
Last Spring Frost May 13
140 growing days
First Fall Frost September 30
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Clark County Soil Profile

Soil Type

Silt Loam

Soil pH

6.0-7.0

Drainage

Well Drained

Comfrey Planting Timeline — Clark County, WI

Comfrey Planting Calendar

Activity When Date Range
Transplant Outdoors May 20 May 20 – Jun 3
Harvest July 22 Jul 22 – Sep 30

Plant 0.5" deep · 8" apart · Rows 12" apart

Month-by-Month Timeline

MonthActivities
January
February
March
April
May Transplant Outdoors
June Transplant Outdoors
July Harvest
August Harvest
September Harvest
October
November
December
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Growing Conditions

☀️ Sun

Partial Shade (3-6 hours)

💧 Water

Moderate — regular watering

📅 Days to Maturity

60–90 days

🧪 Soil pH

Needs 6–7 · Your soil: N/A

🗺️ USDA Zone

Zone 4b

📆 Growing Season

140 days in Clark County

Growing Tips for Clark County

Plant root cuttings 2 inches deep. Choose Bocking 14 variety to prevent self-seeding. Cut leaves 3-4 times per season for mulch or compost. Avoid planting near pathways as it spreads.

Companion Planting

Good Companions

Check more plant combinations with our Companion Planting Checker →

Frequently Asked Questions

When should I plant Comfrey in Clark County, WI?

Clark County is in Zone 4b with an average last frost of May 13. Plan your Comfrey planting based on this frost date — see the calendar above for exact timing.

What planting zone is Clark County, WI?

Clark County, Wisconsin is in USDA Hardiness Zone 4b. The average last spring frost is May 13 and first fall frost is September 30.

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Your Clark County Garden Planner — Free

A 22-page printable planner built for Clark County (Zone 4b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.

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Data sources: USDA Plant Hardiness Zone Map (2023), NOAA 30-Year Climate Normals. Frost dates are based on 50% probability averages for Clark County, WI. Local conditions may vary. Last updated: June 2026.

Sources & credits

Every number on this page traces back to a primary horticulture or government data source. Click through to verify.